RIGHT-VENTRICULAR PERFORMANCE AND CONTRACTILE RESERVE IN PATIENTS WITH SEVERE HEART-FAILURE - ASSESSMENT BY PRESSURE-AREA RELATIONS AND ASSOCIATION WITH OUTCOME

Background Right ventricular (RV) performance appears to be important in patients with severe heart failure. Although clinical assessments o f RV function previously have been limited to load-dependent ejection phase indices, a new method has been developed using the relatively lo ad-insensitive concepts of pressure-volume relations with automated ec hocardiographic measures of RV cross-sectional area as a surrogate for volume. Methods and Results Sixteen patients with New York Heart Asso ciation functional class IV heart failure and group mean left ventricu lar ejection fraction of 20+/-5% were studied. RV pressure-area loops were recorded on-line from echocardiographic measures of RV area and h igh-fidelity pressure during transient inferior vena caval balloon occ lusions. RV contractile reserve was assessed as its functional respons e to an increase in dobutamine from 5.7+/-4.1 to 13.1+/-4.7 mu g/kg, p er minute. Complete data sets were available in 13 patients. Group mea n RV end-systolic elastance (E'es) and maximal elastance (E'max increa sed with augmented dobutamine infusion (2.9+/-1.5 to 5.5+/-3.3 mm Hg/c m(2) and 3.3+/-1.6 to 6.4+/-3.9 mm Hg/cm(2), respectively; P<.01 versu s baseline), although individual responses were variable. During a 30- day follow-up, 9 patients remained unstable, requiring continuous intr avenous inotropic therapy; 6 of these had profound deterioration requi ring mechanical circulatory support. The remaining 4 patients had a co mparatively good short-term outcome with clinical stability. A 100% in crease in RV E'es or E'max was associated with a good short-term outco me (P<.05). Conclusions RV performance can be assessed by pressure-are a relations in patient, with heart failure. RV contractile reserve in response to increases in dobutamine was associated with a good short-t erm outcome and may be of prognostic value in patients with severe hea rt failure.